A Study of the Energy Sources of Herbig-Haro Objects

We make a statistical study of the energy sources of high-velocity phenomena, Herbig-Haro (HH) objects. IRAS counterparts of HH objects are identified.Their colors, brightness, geometric relation to the HH objects and SED are analysed. The sources are found to be concentrated in a band-shaped region in the IRAS color-color diagram. We suggest an explanation of thick surrounding material for this distribution. We propose a new method for identifying the energy sources based on color and brightness. This method is applied to more than 200 HH objects whose energy sources are still unknown. Finally, a group of very young stellar object candidates which have similar properties to the HH energy sources is picked out.Their large-scale distribution is discussed.